模糊逻辑在车辆稳定性控制系统中的应用

Application of fuzzy-logic to vehicle stability control system

探讨了车辆在高速转向的极限运动工况下,利用施加于各车轮不同纵向力产生的辅助横摆力矩来提高车辆动力学稳定性的基本原理.推导了七自由度整车动力学模型,建立了车辆质心侧偏角观测器,并且考虑到车辆参数和运行工况的复杂多变,设计基于模糊控制逻辑的车辆稳定性控制策略,通过控制横摆角速度和质心侧偏角可使车辆对象输出跟踪理想参考模型的输出,用M atlab/S imulink建立车辆仿真模型,对所设计的控制算法进行了数字仿真,最后利用基于dSPACE的硬件在环仿真技术,对设计控制器的性能进行了实验验证.结果表明:所设计的模糊控制器能够显著改善车辆的操纵稳定性,特别是在低附着系数路面工况下.

The principle of enhancing vehicle dynamic stability through additional yaw moment produced by differential longitudinal braking forces in four wheels is discussed as the vehicle is running under limit cornering maneuver. A 7 DOF （ degree of freedom） vehicle dynamic model is derived and a sideslip angle estimator is also constructed. On this basis, a new vehicle stability control strategy based on fuzzy logic is proposed with regard to complex variation of vehicle parameters and working conditions. The developed controller generates the suitable yaw moment which is obtained from the difference of the brake forces of each wheel so that the vehicle follows the target values of the yaw rate and the sideslip angle. Computer simulation was conducted to validate the performance of the designed controller. Finally, an experiment is devised to prove the efficiency of proposed controller with the HILS platform based on Maflab/Simulink/dSPACE. The results show that the fuzzy logic controller can greatly improve the vehicle stability especially under low friction condition.